Thanks very much to Michael W. for his response to my
earlier post. Michael's post made my day . "Quiet
reasonableness" is my aspiration.

Michael, as I understand it, you agree that exchange in
essentially the exchange of equivalents.

However, you argue that, in the performance of the
circulation activities of buying and selling, accounting, etc.
we actually have "production", not exchange - if the
following conditions are fulfilled: (1) the work is done
by wage-labor, (2) in a formally and really subordinated
labor process,
(3) which produces a profit for commercial capitalists.

I agree that the commercial labor process is characterized
by these features, but according to Marx, these features
do not turn circulation into production, or production
functions into circulation functions. As long as the
functions performed by commercial wage-laborers are
buying and selling, etc., i.e. carrying out the exchange of
equivalent values, then their labor does not produce
additional value. The fact that these functions are
performed by wage-laborers does not convert them from
unproductive functions to productive functions. Marx on
this point:

An illusion is introduced here by the function of
merchant's capital. But, without going into further
detail, this much is clear from the start: if we have a
function which, although in and for itself
unproductive, is nevertheless a necessary moment
of reproduction, then when this is transformed, through
the division of labor, from the secondary activity of
many into the exclusive activity of a few,
into their special business, this does not change the
character of the function itself.

[The commercial wage-laborer] performs a
necessary function, because the reproduction process itself
includes unproductive functions. He works as well as the next
man, but the content of his labor creates neither value nor
products. He is himself part of the faux frais of production.
His usefulness does not lie in transforming an unproductive
function into a productive one, or unproductive labor into
productive labor. (C.II. 209-10)

Now it is of course true that commercial capitalists make
a profit. How does this happen? Marx called attention to this
question in Chapter 5 of Volume 1 (p. 266-67 of the
Penguin edition) and answered it in Chapter 17 of
Volume, according to which the profit appropriated by
commercial capitalists is part of the surplus-value
produced by productive labor (not by commercial wage-
labor). In Chapter 17, Marx explained the pricing
mechanism through which commercial capitalists are able
to make this appropriation through the difference
between "producer" prices and "final sales" prices
because the value produced by productive labor is only
partially realized in the price at which the industrial
capitalist sells to the commercial capitalist.

It is also true that the labor of commercial wage-laborers
makes it possible for commercial capitalists to make this
appropriation of surplus-value because they perform the
necessary functions that must be paid for out of surplus-
value.

It is also true that commercial wage-laborers perform
"surplus labor" in a certain sense, but in a different sense
from productive wage-laborers. They are paid wages
that represent say 2 or 3 hours of labor-time; but they
work 8 hours or more. This "surplus labor" does not itself
produce additional surplus-value, but it does reduce the
cost of these unproductive functions, and thereby
REDUCES THE DEDUCTIONS that must be made from
surplus-value to pay for these unproductive functions.
Marx again:

Let us assume he is simply a wage-laborer, even if
one of the better paid. Whatever his payment,
as a wage-laborer, he works part of the day for nothing.
He may receive every day the value product of
weight hours' labor, and function for ten. The two
hours' surplus labor that he performs no more produce
value than do his eight hours of necessary labor, although it is
by means of the latter that a part of the social product is
transferred to him... The costs of circulation that he represents
are reduced by a fifth, from ten hours to eight...
If it is the capitalist who employs these agents, then the
circulation costs of his capital, which form a DEDUCTION from his
receipts, are REDUCED by the non-payment of the two hours.
(C.II. 210; emphasis added)

So, Michael, "labor performed under capitalist relations
of production, but not producing surplus-value" is not an
"oxymoron", but rather is part of the perverted reality of
capitalism, which includes the necessary but
unproductive of circulation. And although commercial
wage-labor does not directly produce surplus-value, this
labor does enable commercial capitalists to appropriate a
part of the total surplus-value produced by productive
labor.

Now, of course Marx could be wrong and this distinction
have no validity whatsover. But I think that at least
Marx provided a coherent rationale for this distinction,
which is what Michael and David have been asking for.
And I also think that this distinction seems to have
considerable explanatory power and in particular
provides a better explanation of the trends in the share
of profit and the rate of profit in the postwar US economy
than any other available explanation - radical or
mainstream (as I have discussed in other recent posts).

So, Michael, I don't expect you to "love it", but can you
live with it - or at least acknowledge that this distinction has a
rational basis?